PLEURISY. - '291 



and there are intervals of relief. While neither will lie down or willingly 

 move, and the pneumonic horse stands fixed as a statue, the pleuritic 

 one shrinks and crouches almost to falling. If he lies down it is on the 

 affected side, when the disease is confined to one side only. The head of 

 the horse, with inflammation of the substance of the lungs, hangs heavily 

 — that of the other is protruded. 



We here derive most important assistance from Auscnliation. In a case 

 of pleurisy we have no crepitating crackling sound, referable to the infil- 

 tration of the blood through the gossamer membrane of the air-cells ; we 

 have not even a louder and distincter murmur. Perhaps there is no 

 variation from the sound of health, or, if there is any difference, the 

 murmur is fainter ; for the pleural membrane is tliickened and its elasticity 

 is impaired, and the sound is not so readily transmitted. There is some- 

 times a slight rubbing sou.nd, and especially towards the superior region 

 of the chest, as if there was friction between the thickened and indurated 

 membranes. 



To this may be added the different character of the coiigh, sore and 

 painful enough in both, but in pneumonia generally hard, and full, and 

 frequent. In pleurisy it is not so frequent, but faint, suppressed, cut short, 

 and attended by a thin ichorous discharge dropping fi'om the nose. 



These are sufficient guides in the early stage of the disease, when it is 

 most of all of importance to distinguish the one from the other. Pleurisy 

 more frequently exists in a purer form than pneumonia, for every now and 

 then death is the result solely of suffocation, but in most cases the struc- 

 ture of the lungs is implicated to a greater or less extent. 



If after a few days the breathing becomes a little more natural, the 

 inspiration lengthened and regular, and the expiration, although still pro- 

 longed, is suffered to be completed— if the twitchings are less evident 

 and less frequent — if the cough can be fully expressed — if the pulse 

 softens, although it may not diminish in frequency, and if the animal 

 begins to lie down, or walks about of his own accord, there is hope of 

 recovery. But if the pulse quickens and, although smaller, yet possesses 

 the wiry character of inflammation — if the gaze at the flanks, previously 

 by starts, becomes fixed as well as anxious, and the difficulty of breathing 

 continues (the difficulty of accomplislimg it, although the efforts are 

 oftener repeated) — if patches of sweat break out, and the animal gets 

 restless — paws — shifts his posture every minute — is unable longer to 

 stand yet hesitates whether he shall lie down — determines on it again and 

 again, but fears, and at length drops rather than lies gently down, a fatal 

 termination is at hand. 



The most frequent cause of death is effusion in the chest (hydrothorax), 

 compressing the lungs on every side, rendering expiration difficult and at 

 length impossible, and destroying the animal by suffocation. For some 

 time before his death the effusion and extent will be evident enough. The 

 violence of the symptoms will suddenly abate, the pulse falling from eighty 

 or ninety to forty or fifty, and in some cases becoming softer in its character. 

 The membranes also will assume a pale colour as the effusion increases. 

 The animal not only walks unwillingly, but on the slightest exercise his 

 pulse is strangely acelerated ; the feeling of suffocation comes over him, 

 and he stops suddenly, looks wildly about, and trembles ; but he quickly 

 recovers himself, and proceeds. There is frequently also, when the effusion 

 is confirmed, oedema of some external part, and that occasionally to a very 

 great extent. This is oftenest observed in the abdomen, the chest, and 

 the point of the breast. The very commencement of effusion may be 

 detected b}^ auscultation. There will be the cessation of the respiratory 

 murmur at the sternum, and the increased grating — not the crepitating 



u 2 



